build(deps): bump mjml from 4.18.0 to 5.4.0

Bumps [mjml](https://github.com/mjmlio/mjml/tree/HEAD/packages/mjml) from 4.18.0 to 5.4.0.
- [Release notes](https://github.com/mjmlio/mjml/releases)
- [Commits](https://github.com/mjmlio/mjml/commits/v5.4.0/packages/mjml)

---
updated-dependencies:
- dependency-name: mjml
  dependency-version: 5.4.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]